The present invention relates to a water stopping configuration of linear members and a method of water stopping the linear members which water stops interstices between wires forming a wire harness, interstices between core wires of a sheathed wire, etc. Incidentally, “water stopping” in the description of the present invention is not limited to the prevention of intrusion of water, but means that it effectively acts on a liquid containing water, oil, alcohol, etc., as a whole, and here description will be made using “water stopping” generally extensively used as a designation.
As a water stopping method of sealing interstices between wires of a wire harness (that is, between linear members forming the wire harness) by a water stopping material, there is known one in which as shown in FIG. 6, the water stopping material 200 is coated onto a plurality of wires W (that is, a bundle of wires W) forming the wire harness, and thereafter a sheet (that is, a covering member) 10 is wound on the coated portion, and then the sheet 10 is temporarily fixed by clips (not shown), and after the water stopping material 200 is cured, the clips are removed from the sheet 10, and this portion of the sheet 10 is covered with a neck portion of a grommet (not shown), and the grommet is fixed to the wire harness (for example, see Patent Literature 1). In this case, a width B of filling of the water stopping material 200 (a length covered by the sheet 10) in the operation is larger than a necessary water stopping width A of the water stopping material 200.
In this method, after the water stopping material 200 is coated, this portion is merely wrapped in the sheet 10, and therefore the water stopping material 200 flows through the interstices between the wires W to the outside of the necessary water stopping width A because of a capillary phenomenon, so that there is a fear that a water stopping performance as expected may not be secured. And besides, there is a fear that projecting portions 201 of the water stopping material 200 projecting to the outside of the sheet 10 may smear the surroundings. The wire harness, in which the water stopping material 200 thus penetrates into the interstices between the wires W and into a gap between the wires W and the sheet 10 such that the projecting portions 201 become large, and thereafter is cured, has a hard portion over a long distance in a direction of its length, and therefore flexibility necessary for the wire harness is lowered.
Next, one example of a water stopping method of sealing interstices between core wires of a sheathed wire (that is, between linear members forming the sheathed wire) by a water stopping material will be described with reference to FIG. 7. As shown in FIG. 7, the sheathed wire 51 has an insulating sheath (that is, a covering member) 54 provided around a plurality of core wires (conductors) 53 thereof. A connection terminal 52 is press-clamped (that is, press-fastened) to an end portion of this sheathed wire 51.
For press-clamping the connection terminal 52 to the sheathed wire 51, the end portion of the sheathed wire 51 where the core wires 53 are exposed by removing the insulating sheath 54 is set between barrels 55 of the connection terminal 52, and the barrels 55 are press-fastened to be closed, thereby fixing the core wires 53 and the insulating sheath 54 to the connection terminal 52 by press-clamping.
In the water stopping method of effecting the water stopping between the core wires 53 of the sheathed wire 51 with the connection terminal 52, a water stopping material having flowability is supplied dropwise to the end portion of the sheathed wire 51 from the upper side (that is, from a forward side when facing FIG. 7) while aiming at a center of a broken-line ellipse 60, and the water stopping material is caused to penetrate into the inside of the insulating sheath 54 in an attempt to fill the interstices between the core wires 53 and a gap between the core wires 53 and an inner surface of the insulating sheath 54 with the water stopping material. Incidentally, an adhesive such as Aron Alpha (registered trademark) produced by To a Gosei Kabushiki Kaisha is used as the water stopping material.
However, in the water stop processing effected by this method, because of a capillary phenomenon, the water stopping material will not flow uniformly into the interstices between the core wires 53 and into the gap between the core wires 53 and the inner surface of the insulating sheath 54. Therefore, even when a specified amount of water stopping material is supplied dropwise toward the center of the broken-line ellipse 60, there is a high possibility that interstices are formed between the core wires 53 or between the core wires 53 and the insulating sheath 54 (that is, the interstices remain), so that the desired water stopping effect can not be obtained.
Therefore, when a large amount of water stopping material is supplied dropwise toward the center of the broken-line ellipse 60, the water stopping material effectively acts to fill in the interstices, but on the other hand there arises a drawback that the water stopping material penetrates beyond the necessary water stopping width. Namely, the sheathed wire 51, in which the water stopping material penetrates into the interstices between the core wires 53 and into the gap between the core wires 53 and the insulating sheath 54 to an extent exceeding the necessary water stopping width, and then is cured, will have a hard portion over a long distance in the direction of its length, and therefore flexibility necessary for the sheathed wire 51 (that is, the wire harness) becomes low.
Thus, in the water stopping configuration in which it is difficult to confirm how far the water stopping material, caused to penetrate into the interstices between the linear members, has penetrated, a variation in reliability of the water stop processing develops with the above water stopping method.    [Patent Literature 1] JP-A-2005-73389 Publication